Intervertebral implant having mechanical securement

ABSTRACT

An intervertebral implant for implantation between an upper vertebral body and a lower vertebral body is disclosed. The intervertebral implant includes a body portion through which a first and a second pathway pass. A first straight anchor is movable in a straight path through the first pathway and a second straight anchor is movable in a straight path through the second pathway. A locking member is movable between an open position and a closed position to either block or allow the withdrawal of the first and second straight anchors.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. patent applicationSer. No. 14/836,478 filed on Aug. 26, 2015, which is acontinuation-in-part of U.S. patent application Ser. No. 14/636,305filed on Mar. 3, 2015, and which are hereby incorporated by reference intheir entirety.

BACKGROUND

The present invention relates to intervertebral implants forimplantation between vertebral bodies.

Intervertebral implants are placed between vertebral bodies to replacedegenerated intervertebral discs. They can be used as an alternative tospinal fusion to reduce pain in the neck and back while still allowingmotion in the spine. Many intervertebral implants are designed to be fitbetween vertebral bodies but are not easily removable. Removal ofteninvolves destruction of the implant, so it may not be reused if removedfrom the spine. It would be desirable for an intervertebral implant toallow easy removal from the spine and for the implant to be reusableonce removed.

Thus, there is a need for improvement in this field.

SUMMARY

The claims, and only the claims, recite the invention. In summary, itmay include an intervertebral implant for implantation between an uppervertebral body and a lower vertebral body. The implant includes a bodyportion having a top side for contact with the upper vertebral body, abottom side for contact with the lower vertebral body, and an anteriorside between the top and bottom sides. The implant also includes a platethat is removably attachable to the body portion. The plate includes atop side for contact with the upper vertebral body, a bottom side forcontact with the lower vertebral body, and a posterior side and ananterior side between the top and bottom sides. The plate defines inspace a Z-axis generally in a cranial-caudal orientation therethroughand a Y-axis perpendicular to the Z-axis and passing through theanterior side.

The implant includes a first pathway through the plate and a firststraight anchor movable in an straight path through the first pathway topenetrate into the upper vertebral body. It also includes a secondpathway through the plate and a second straight anchor movable in anstraight path through the second pathway to penetrate into the lowervertebral body.

The implant may include a locking member that is selectively movablebetween an open position and a closed position in a movement path thatis generally transverse to the Y-axis. When the locking member is movedto the closed position it is located anteriorly of the first straightanchor and the second straight anchor, blocking the withdrawal of thefirst and second straight anchor from the anterior side of the plate.The locking member is selectively movable along a generally transversemovement path from the closed position to the open position to allowwithdrawal of the first straight anchor and the second straight anchorfrom the anterior side of the plate to facilitate removal of the implantfrom between the upper and lower vertebral bodies.

Further forms, objects, features, aspects, benefits, advantages, andembodiments of the present invention will become apparent from adetailed description and drawings provided herewith.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view (see cut line 1-1 in FIG. 3B) of anintervertebral implant for implantation between an upper vertebral bodyand a lower vertebral body.

FIG. 2 is a partial top plan view of the body portion of FIG. 1 showingan opening used for removal.

FIG. 3A is a perspective view of an intervertebral implant including alocking member comprising a gate.

FIG. 3B is a front view of the intervertebral implant of FIG. 3Aconfigured in an unlocked position.

FIG. 3C is a front view of the intervertebral implant of FIG. 3A withthe locking member configured in a locked position.

FIG. 3D is a top plan view of the intervertebral implant of FIG. 3B.

FIG. 4A is a front view of an intervertebral implant including a lockingmember comprising a cam configured in an unlocked position.

FIG. 4B is a front view of the intervertebral implant of FIG. 4A withthe locking member configured in a locked position.

FIG. 4C is a top plan view of the intervertebral implant of FIG. 4A.

FIG. 5A is a front view of an intervertebral implant including a lockingmember comprising a lateral slide configured in an unlocked position.

FIG. 5B is a front view of the intervertebral implant of FIG. 5A withthe locking member configured in a locked position.

FIG. 5C is a top plan view of the intervertebral implant of FIG. 5A.

FIG. 6 is a side view of a slap hammer with a removal tool feature.

FIG. 7 is a cross-sectional view of an intervertebral implant forimplantation between an upper vertebral body and a lower vertebral body.

FIG. 8 is a perspective view of a body portion of the intervertebralimplant of FIG. 7.

FIG. 9 is a side cross-sectional view of a plate of the intervertebralimplant of FIG. 7.

FIG. 10 is a perspective view of the intervertebral implant of FIG. 7including a locking member comprising a gate.

FIG. 11 is a cross-sectional view of an intervertebral implant forimplantation between an upper vertebral body and a lower vertebral body.

FIG. 12A is a a front view of an intervertebral implant including alocking member comprising a gate configured in an unlocked position.

FIG. 12B is the intervertabral implant of FIG. 12A with the lockingmember configured in a locked position.

FIG. 13A is a a front view of an intervertebral implant including alocking member comprising a cam configured in an unlocked position.

FIG. 13B is the intervertebral implant of FIG. 13A with the lockingmember configured in a locked position.

FIG. 14A is a a front view of an intervertebral implant including alocking member comprising a lateral slide configured in an unlockedposition.

FIG. 14B is the intervertebral implant of FIG. 14A with the lockingmember configured in a locked position.

FIG. 15 is a side cross-sectional view of a plate for an intervertebralimplant.

FIG. 16 is a side cross-sectional view of an insertion tool for theintervertebral implant of FIG. 11.

DESCRIPTION OF THE SELECTED EMBODIMENTS

For the purpose of promoting an understanding of the principles of theinvention, reference will now be made to the embodiments illustrated inthe drawings and specific language will be used to describe the same. Itwill nevertheless be understood that no limitation of the scope of theinvention is thereby intended. Any alterations and further modificationsin the described embodiments, and any further applications of theprinciples of the invention as described herein are contemplated aswould normally occur to one skilled in the art to which the inventionrelates. One embodiment of the invention is shown in great detail,although it will be apparent to those skilled in the relevant art thatsome features that are not relevant to the present invention may not beshown for the sake of clarity.

With reference to the drawing Figures, for example FIGS. 1-5C, anintervertebral implant 100 for implantation between an upper vertebralbody 105 and a lower vertebral body 110 is shown. The intervertebralimplant 100 includes a body portion 120 having a top side 122 forcontact with the upper vertebral body 105 and a bottom side 124 forcontact with the lower vertebral body 110. The intervertebral implant100 also includes an anterior side 126 between the top and bottom sides122, 124. The body portion 120 defines, in space, a Z-axis generally ina cranial-caudal orientation therethrough and a Y-axis perpendicular tothe Z-axis and passing through the anterior side 126.

A first pathway 130 extends through the body portion 120 from theanterior side 126 to the top side 122 of the body portion. A firstarcuate anchor 135 is movable in an arcuate path through the firstpathway 130 to penetrate into the upper vertebral body 105.

A second pathway 140 extends through the body portion 120 from theanterior side 126 to the bottom side 124 of the body portion 120. Asecond arcuate anchor 145 is movable in an arcuate path through thesecond pathway 140 to penetrate into the lower vertebral body 110.

One or more locking member 155, 160, 165 is selectively movable betweenan open position and a closed position in a movement path that isgenerally transverse to the Y-axis. Upon transverse movement to theclosed position, the locking member is located anteriorly of the firstarcuate anchor 135 and the second arcuate anchor 145. The locking memberblocks the withdrawal of the first arcuate anchor 135 and the secondarcuate anchor 145 from the anterior side 126 of the body portion 120.

The locking member is selectively movable along the generally transversemovement path from the closed position to the open position to allowwithdrawal of the first arcuate anchor 135 and the second arcuate anchor145 from the anterior side 126 of the body portion 120. Withdrawal offirst arcuate anchor 135 and second arcuate anchor 145 facilitatesremoval of the body portion from between the upper and lower vertebralbodies 105, 110.

One feature that is optional, but not required, may be that the lockingmember comprises a lateral gate 155 (see FIGS. 3A, 3B, 3C, and 3D), andthe movement path of the locking member is with the lateral gatepivoting on a hinge axis.

One feature that is optional, but not required, may be that the lockingmember comprises a cam or other non-circular rotating member 160 (seeFIGS. 4A and 4B), and the movement path of the locking member is withthe cam 160 pivoting on a cam axis 162 which is generally parallel tothe Y-axis. The cam may have a radially extended segment that, uponpivoting on the cam axis, is movable generally transverse to the Y-axisto block the first arcuate anchor 135 and the second arcuate anchor 145from withdrawal.

One feature that is optional, but not required, may be that the lockingmember comprises a lateral slide 165 (see FIGS. 5A and 5B), and themovement path of the locking member is along a track 168 that isgenerally transverse to the Y-axis.

One feature that is optional, but not required, may be that the firstarcuate anchor 135 has a first front edge 137 that extends anteriorly ofa front surface along the anterior side 126 of the body portion 120 whenimplanted and penetrating into the upper vertebral body 105. Also thesecond arcuate anchor 145 has a second front edge 147 that extendsanteriorly of the front surface along the anterior side 126 of the bodyportion 120 when implanted and penetrating into the lower vertebral body110.

One feature that is optional, but not required, may be that the firstarcuate anchor 135 includes a first means for being grabbed by a toolfor anterior withdrawal from the body portion. The second arcuate anchor145 includes a second means for being grabbed by a tool for anteriorwithdrawal from the body portion.

One feature that is optional, but not required, may be that the firstmeans for being grabbed may include a first hole 139 in the firstarcuate anchor 135 located near the first front edge 137. The secondmeans for being grabbed may include a second hole 149 in the secondarcuate anchor 145 located near the second front edge 147. One featurethat is optional, but not required, may be that the anchor 135, 145includes an opening 139, 149 (see FIG. 2). The openings may beconfigured to receive a removal tool hook 174 for removing the implantfrom between the upper vertebral body 105 and the lower vertebral body110. Removal tool hook 174 may be a dedicated tool; or, optionally itmay be part of another tool such as a slap hammer 200 (FIG. 6). Othertools, such as pliers may be used. Optionally, however, instead of or inaddition to one or more such holes, the means may include otherstructure, including a ridge, groove, bump, high friction surface and/orcombinations thereof.

One feature that is optional, but not required, may be that the bodyportion 120 is made of a metallic material having a Rockwell hardness[on the A-scale] of at least 35 making it resistant to destructiveimplant removal.

One feature that is optional, but not required, may be that the firstarcuate anchor 135 does not have a detent lock for locking itpermanently in place within the first pathway 130. Also, optionally, thesecond arcuate anchor 145 does not have a detent lock for locking itpermanently in place within the second pathway 140.

One feature that is optional but not required is a cavity 101 (FIG. 1)for bone chips and/or other bone fusion material.

With reference to FIGS. 7-10, an alternative embodiment of anintervertebral implant for implantation between an upper vertebral body105 and a lower vertebral body 110 is shown. The intervertebral implant300 includes a plate 325 that attaches to the body portion 320 of theintervertebral implant 300.

Plate 325 (see FIG. 9) has a top side 332 for contact with the uppervertebral body 105 and a bottom side 334 for contact with the lowervertebral body 110. Plate 325 also includes and a posterior side 328 andan anterior side 326 between the top side 332 and bottom side 334. Plate325 defines in space a Z-axis generally in a cranial-caudal orientationtherethrough and a Y-axis perpendicular to the Z-axis and passingthrough the anterior side 326 of plate 325.

A first pathway 330 through plate 325 extends from the anterior side 326to the top side 332 of plate 325. A first arcuate anchor 335 is movablein an arcuate path through first pathway 330 to penetrate into the uppervertebral body 105.

A second pathway 340 through plate 325 extends from the anterior side326 to the bottom side 334 of plate 325. A second arcuate anchor 345 ismovable in an arcuate path through second pathway 340 to penetrate intothe lower vertebral body 110.

Plate 325 is adapted to be removably attachable to body portion 320.Body portion 320 (see FIG. 8) has a top side 322 for contact with theupper vertebral body 105 and a bottom side 324 for contact with thelower vertebral body 110. Body portion 320 also includes and an anteriorside 327 between top side 322 and bottom side 324. One or more lockingmember 155, 160, or 165 (as shown in FIGS. 3A, 4A, and 5A) isselectively movable between an open position and a closed position in amovement path that is generally transverse to the Y-axis. Upontransverse movement of the locking member to the closed position, thelocking member is located anteriorly of first arcuate anchor 335 andsecond arcuate anchor 345, blocking their withdrawal from the anteriorside 326 of plate 325.

The locking member 155, 160, or 165 is selectively movable along thegenerally transverse movement path from the closed position to the openposition to allow withdrawal of first arcuate anchor 335 and secondarcuate anchor 345 from the anterior side 326 of plate 325 to facilitateremoval of the intervertebral implant 300 from between the upper andlower vertebral bodies.

One feature that is optional, but not required, may be that the anteriorside 327 of body portion 320 may include a threaded connectioninterface, such as a tapped opening 329, and the posterior side 328 ofplate 325 also includes a threaded connection interface, such as athreaded member 336. The threaded connection interfaces on body portion320 and plate 325 may be mated to attach body portion 320 to plate 325.As an example, threaded member 336 may be inserted into and engagetapped opening 329 to attach plate 325 to body portion 320. In otherembodiments, a tapped opening may be included on plate 325 and athreaded member may be included on body portion 320.

One feature that is optional, but not required, may be that firstarcuate anchor 335 has a first front edge 337 that extends anteriorly ofa front surface along anterior side 326 of plate 325 when implanted andpenetrating into the upper vertebral body 105. Also, second arcuateanchor 345 has a second front edge 347 that extends anteriorly of thefront surface along anterior side 326 of plate 325 when implanted andpenetrating into the lower vertebral body 110.

One feature that is optional, but not required, may be that firstarcuate anchor 335 includes a first means for being grabbed by a toolfor anterior withdrawal from plate 325. Also, second arcuate anchor 345includes a second means for being grabbed by a tool for anteriorwithdrawal from plate 325.

One feature that is optional, but not required, may be that the firstmeans for being grabbed comprises a first hole 339 in first arcuateanchor 335 located near first front edge 337. The second means for beinggrabbed comprises a second hole 349 in second arcuate anchor 345 locatednear second front edge 349.

One feature that is optional, but not required, may be that body portion320 and plate 325 are made of a metallic material having a Rockwellhardness [on the A-scale] of at least 35 making it resistant todestructive implant removal.

One feature that is optional, but not required, may be that firstarcuate anchor 335 does not have a detent lock for locking itpermanently in place within first pathway 330. Also, second arcuateanchor 345 does not have a detent lock for locking it permanently inplace within second pathway 340.

One feature that is optional, but not required, may be that the lockingmember comprises a lateral gate 155 (see FIGS. 3A, 3B, 3C, 3D, and 10),and the movement path of the locking member is with the lateral gatepivoting on a hinge axis.

One feature that is optional, but not required, may be that the lockingmember comprises a cam 160 (see FIGS. 4A, 4B, 4C). The movement path isthe cam pivoting on a cam axis which is generally parallel to theY-axis. The cam has a radially extended segment that, upon pivoting onthe cam axis, is movable generally transverse to the Y-axis to blockfirst arcuate anchor 335 and second arcuate anchor 345 from withdrawal.

One feature that is optional, but not required, may be that the lockingmember comprises a lateral slide 165 (see FIGS. 5A, 5B, 5C). Themovement path of lateral slide 165 is along a track that is generallytransverse to the Y-axis.

One feature that is optional but not required is a cavity 301 (FIG. 7)for bone chips an/dor other bone fusion material.

With reference to FIGS. 11-16, an alternative embodiment of anintervertebral implant 400 for implantation between an upper vertebralbody 105 and a lower vertebral body 110 is shown. The intervertebralimplant 400 includes a body portion 420 having a top side 422 forcontact with the upper vertebral body 105 and a bottom side 424 forcontact with the lower vertebral body 110. The intervertebral implant400 also includes an anterior side 426 between the top and bottom sides422, 424. The body portion 420 defines, in space, a Z-axis generally ina cranial-caudal orientation therethrough and a Y-axis perpendicular tothe Z-axis and passing through the anterior side 426.

A first pathway 430 extends through the body portion 420 from theanterior side 426 to the top side 422 of the body portion 420. A firststraight anchor 435 is movable in a straight path through the firstpathway 430 to penetrate into the upper vertebral body 105.

A second pathway 440 extends through the body portion 420 from theanterior side 426 to the bottom side 424 of the body portion 420. Asecond straight anchor 445 is movable in a straight path through thesecond pathway 440 to penetrate into the lower vertebral body 110.

One feature that is optional, but not required, may be that theintervertebral implant 400 includes one or more locking member 455, 460,465 that is selectively movable between an open position and a closedposition in a movement path that is generally transverse to the Y-axis.Upon transverse movement to the closed position, the locking member islocated anteriorly of the first straight anchor 435 and the secondstraight anchor 445. The locking member blocks the withdrawal of thefirst straight anchor 435 and the second straight anchor 445 from theanterior side 426 of the body portion 420.

The locking member is selectively movable along the generally transversemovement path from the closed position to the open position to allowwithdrawal of the first straight anchor 435 and the second straightanchor 445 from the anterior side 426 of the body portion 420.Withdrawal of first straight anchor 435 and second straight anchor 445facilitates removal of the body portion from between the upper and lowervertebral bodies 105, 110.

One feature that is optional, but not required, may be that firststraight anchor 435 has a first front edge 437 that extends anteriorlyof a front surface along anterior side 426 of body portion 420 whenimplanted and penetrating into the upper vertebral body 105. Also,second straight anchor 445 has a second front edge 447 that extendsanteriorly of the front surface along anterior side 426 of body portion420 when implanted and penetrating into the lower vertebral body 110.

One feature that is optional, but not required, may be that firststraight anchor 435 includes a first means for being grabbed by a toolfor anterior withdrawal from body portion 420. Also, second straightanchor 445 includes a second means for being grabbed by a tool foranterior withdrawal from body portion 420.

One feature that is optional, but not required, may be that the firstmeans for being grabbed comprises a first hole 439 in first straightanchor 435 located near first front edge 437. The second means for beinggrabbed comprises a second hole 449 in second straight anchor 445located near second front edge 447.

One feature that is optional, but not required, may be that body portion420 is made of a metallic material having a Rockwell hardness [on theA-scale] of at least 35 making it resistant to destructive implantremoval.

One feature that is optional, but not required, may be that firststraight anchor 435 does not have a detent lock for locking itpermanently in place within first pathway 430. Also, second straightanchor 445 does not have a detent lock for locking it permanently inplace within second pathway 440.

One feature that is optional, but not required, may be that the lockingmember comprises a lateral gate 455 (see FIGS. 12A and 12B), and themovement path of the locking member is with the lateral gate pivoting ona hinge axis.

One feature that is optional, but not required, may be that the lockingmember comprises a cam 460 (see FIGS. 13A and 13B). The movement path isthe cam pivoting on a cam axis which is generally parallel to theY-axis. The cam has a radially extended segment that, upon pivoting onthe cam axis, is movable generally transverse to the Y-axis to blockfirst straight anchor 435 and second straight anchor 445 fromwithdrawal. In some embodiments, there may be a single cam 460 that ispositioned between pathways 430 and 440. In other embodiments, eachpathway 430 and 440 may have its own cam 460.

One feature that is optional, but not required, may be that the lockingmember comprises a lateral slide 465 (see FIGS. 14A and 14B). Themovement path of lateral slide 465 is along a track 468 that isgenerally transverse to the Y-axis.

One feature that is optional, but not required, may be that the firstpathway 430 and the second pathway 440 are positioned on the samehorizontal plane at the anterior side 426 of the body portion 420.

One feature that is optional but not required is a cavity 401 (FIG. 1)for bone chips and/or other bone fusion material.

One feature that is optional, but not required, may be that theintervertebral implant 400 includes an insertion tool 470 that has afirst straight insertion pathway 472 and a second straight insertionpathway 474 (see FIG. 16). A leading edge 476 of the insertion tool 470is sized to engage the anterior side 426 of intervertebral implant 400,so that the first insertion pathway 472 may align with the secondpathway 440 and the second insertion pathway 474 may align the withfirst pathway 430. The insertion pathways 472, 474 are adapted toreceive one of the anchors 435, 445. A tamp 480 may be included with theinsertion tool 470. An end 482 of the tamp 480 is angled so that tamp480 may be used to push anchors 435, 445 through the insertion pathways472, 474 of the insertion tool and into the pathways 430, 440 ofintervertebral implant 400.

One feature that is optional, but not required, may be that theintervertebral implant 400 includes a plate 425 that attaches to thebody portion 320 (see FIG. 8) of an intervertebral implant. Plate 425(see FIG. 15) has a top side 432 for contact with the upper vertebralbody 105 and a bottom side 434 for contact with the lower vertebral body110. Plate 425 also includes a posterior side 428 and an anterior side426 between the top side 432 and bottom side 434. Plate 425 defines inspace a Z-axis generally in a cranial-caudal orientation therethroughand a Y-axis perpendicular to the Z-axis and passing through theanterior side 426 of plate 425. A first pathway 430 extends in astraight path through plate 425 from the anterior side 426 to the topside 422 of the plate. A second pathway 440 extends in a straight paththrough plate 425 from the anterior side 426 to the bottom side 424 ofthe plate.

One feature that is optional, but not required, may be that the anteriorside 327 of body portion 320 may include a threaded connectioninterface, such as a tapped opening 329, and the posterior side 428 ofplate 425 also includes a threaded connection interface, such as athreaded member 436. The threaded connection interfaces on body portion320 and plate 425 may be mated to attach body portion 320 to plate 425.As an example, threaded member 436 may be inserted into and engagetapped opening 329 to attach plate 425 to body portion 320. In otherembodiments, a tapped opening may be included on plate 425 and athreaded member may be included on body portion 320.

One feature that is optional, but not required, may be that plate 425 ismade of a metallic material having a Rockwell hardness [on the A-scale]of at least 35 making it resistant to destructive implant removal.

As used here (claims, specification, and other definitions) thefollowing terms have the following meaning:

Articles and phases such as, “the”, “a”, “an”, “at least one”, and “afirst”, “comprising”, “having” and “including” here are not limited tomean only one, but rather are inclusive and open ended to also include,optionally, two or more of such elements and/or other elements. In termsof the meaning of words or terms or phrases herein, literal differencestherein are not superfluous and have different meaning, and are not tobe synonymous with words or terms or phrases in the same or otherclaims.

The term “means for” in a claim invokes 35 U.S.C. §112(f), literallyencompassing the recited function and corresponding structure andequivalents thereto. Its absence does not, unless there otherwise isinsufficient structure recited for that claim element. Nothing herein orelsewhere restricts the doctrine of equivalents available to thepatentee.

The term “and/or” is inclusive here, meaning “and” as well as “or”. Forexample, “P and/or Q” encompasses, P, Q, and P with Q; and, such “Pand/or Q” may include other elements as well.

The term “anchor” as used herein has the meaning, an object used toattach and secure one object to another object.

The term “anterior” as used herein has the meaning, being situatednearest or toward the front of the body. With respect to the spine, theanterior is considered to be the side of the spine closest to thestomach or the throat.

The term “anteriorly” as used herein has the meaning, positioned in alocation more anterior with respect to another object where the anteriorrefers to a position nearer to the front of a reference point.

The term “arcuate” as used herein has the meaning, to be curved, in anarc of a circle.

The term “arcuate path” as used herein has the meaning, a track oropening used to guide movement that has a generally arcuate, or curved,shape.

The term “blocking their withdrawal” as used herein has the meaning,positioned to obstruct and disallow the removal of an object.

The term “body portion” as used herein has the meaning, the main orprincipal part of an object. More specifically, it refers to a part of avertebra implant that contacts the vertebral body of a neighboringvertebra.

The term “cam” as used herein has the meaning, a rotating part that isnon-circular.

The term “contact” as used herein has the meaning, the state orcondition of physical touching between two objects. As used, contactrequires at least one location where objects are directly or indirectlytouching, with or without any other member(s) material in between.

The term “cranial-caudal orientation” as used herein has the meaning, inthe direction along an axis running vertically toward and away from a(standing) patient's skull.

The term “destructive implant removal” as used herein has the meaning,removal of an implant by causing harm or damage to the implant so it maynot be reused after removal.

The term “detent lock” as used herein has the meaning, a lockingmechanism that includes a snap-in lock. When engaged, the releasablepart prevents motion, and motion is not allowed until the part isreleased.

The term “facilitate” as used herein has the meaning, to aid or helpaccomplish an action or a process to make that action or process easier.The act of facilitation does not need to accomplish the action orprocess entirely on its own.

The term “front edge” as used herein has the meaning, the outer limit ofan object, where the term front is used to denote the anterior-mostlimit of the object.

The term “front surface” as used herein has the meaning, an exteriorsurface which may or may not be the anterior most surface.

The term “gate” as used herein has the meaning, a structure that swingson a pivot or hinge.

The term “hinge” as used herein has the meaning, a jointed device onwhich a swinging part is attached so that it may rotate about the joint.The hinge may allow the part to rotate in a full circle, or rotation maybe limited to an arc.

The term “hole” as used herein has the meaning, a hollow opening withina body, structure, or an object. It can be any shape.

The term “horizontal plane” as used herein has the meaning, a planeacross the body that forms right angles with the coronal and sagittalplanes. As an example, the Z-axis forms a right angle with a horizontalplane.

The term “locking it permanently” as used herein has the meaning,applying a lock to a structure so that it cannot be moved. Once the lockis put in place, it cannot be removed so that motion of the structure isnever allowed absent destructive implant removal.

The term “locking member” as used herein has the meaning, an object usedto prevent the movement of another object or objects. For example, alocking member may be any structure used to prevent the movement of ananchor. A locking member may be fixed or may be movable.

The term “means for being grabbed by a tool” as used herein has themeaning, any structure that is configured to be able to be gripped orseized or hooked by a tool. The structure may be a portion of, orconnected to a larger structure. It may include holes, ridge, bumps,grooves, and high friction surfacing.

The term “pathway” as used herein has the meaning, a track or an openarea that is used to guide the movement of another object. A pathway maytake various shapes, for example, it may be straight and/or curved.

The term “perpendicular” as used herein has the meaning, meeting at asubstantially 90 degree angle. Small variations from 90 degrees withinthe range of acceptable tolerance limits are allowed.

The term “plate” as used herein has the meaning, a portion of anintervertebral implant that is attachable to the body portion. A platemay be attached to the anterior side of the body portion or may beattached to a different side or multiple sides of the body portion. Aplate may include pathways for receiving anchors or other objects.

The term “posterior” as used herein has the meaning, being situatednearest or toward the back of the body. With respect to the spine, theposterior is considered to be the side of the spine closest to thepatient's back. The posterior is the opposite side from the anterior.

The term “removably attachable” as used herein has the meaning, to beable to fasten, connect, or join two separate objects in a manner thatallows the objects to be detached without damaging the objects to theextent that the object could not be reused.

The term “removal tool” as used herein has the meaning, any structure orobject that may be used to assist in the removal of the implant oranchor from between vertebral bodies without causing damage to theimplant. As an example, the removal tool may be a wire, pliers, or ahook structure.

The term “Rockwell hardness” as used refers to the scale commonly usedto determine the hardness of a material where hardness is determinedbased on the depth of penetration of an indenter. The A-scale uses a120° diamond cone indenter with a 60 kgf load.

The term “side” as used herein has the meaning, one of the faces on thesurface of an object. An object can have multiple faces with a varietyof orientations. For example, an object may have a front side, a bottomside, a back side, or a top side.

The term “slide” as used herein has the meaning, a structure that isable to move along the surface, track or grove of another object.

The term “straight” as used herein has the meaning, extending or movingwithin a single axis without curving or bending.

The term “threaded connection interface” as used herein has the meaning,a surface that is adapted to attach to another surface using a threadedconnection. One example of a threaded connection interface may be asurface that includes a tapped opening. Another threaded connectioninterface may be a surface that includes a threaded member extendingfrom the surface that may be inserted into a threaded opening.Representative examples of threaded members include a screw, a nut andbolt, or a threaded rod.

The term “track” as used herein has the meaning, a path or a route thatdefines the movement of an object. When an object is on a track, themovement of that object is confined to the position of the track.

The term “transverse” as used herein has the meaning, situated orextending across an object or an axis.

The term “vertebral body” as used herein has the meaning, the largest,cylindrical part of a vertebra. The vertebra is a bone or object thatforms part of the spinal column. The vertebral body could be composed ofbone or it can be an implant formed from any variety of materials thatwould be useful to replace bone such as titanium, stainless steel, orother metallic or non-metallic compounds.

The term “withdrawal” as used herein has the meaning, the action ofremoving or taking away something for a particular location.

The term “Y-axis” as used herein has the meaning, a central line of abody orientated in the Y-direction. As used in this application withrespect to the human body, the Y-direction is perpendicular to theZ-axis passing through the anterior side of the vertebral implant, forexample, from the stomach to the back.

The term “Z-axis” as used herein has the meaning, a central line of abody orientated in the Z-direction. As used in this application withrespect to the human body, the Z-direction follows a cranial-cradiumorientation, extending from the head through the feet.

The invention may include any one or more articles or devices made byany of the claimed methods and/or may by different methods but with aclaimed composition.

The language used in the claims and the written description and in theabove definitions is to only have its plain and ordinary meaning, exceptfor terms explicitly defined above. Such plain and ordinary meaning isdefined here as inclusive of all consistent dictionary definitions fromthe most recently published (on the filing date of this document)general purpose Webster's dictionaries and Random House dictionaries.

While the invention has been illustrated and described in detail in thedrawings and foregoing description, the same is to be considered asillustrative and not restrictive in character, it being understood thatonly the preferred embodiment has been shown and described and that allchanges, equivalents, and modifications that come within the spirit ofthe inventions defined by following claims are desired to be protected.All publications, patents, and patent applications cited in thisspecification are herein incorporated by reference as if each individualpublication, patent, or patent application were specifically andindividually indicated to be incorporated by reference and set forth inits entirety herein.

The invention claimed is:
 1. An intervertebral implant for implantationbetween an upper vertebral body and a lower vertebral body, comprising:a body portion having a top side for contact with the upper vertebralbody and a bottom side for contact with the lower vertebral body and ananterior side between said top and bottom sides, wherein said bodyportion defines in space a Z-axis generally in a cranial-caudalorientation therethrough and a Y-axis perpendicular to said Z-axis andpassing through said anterior side; a first pathway through said bodyportion, said first pathway extending from said anterior side of saidbody portion to said top side of said body portion; a first straightanchor movable in a straight path through said first pathway topenetrate into the upper vertebral body; a second pathway through saidbody portion, said second pathway extending from said anterior side tosaid bottom side of said body portion; a second straight anchor movablein a straight path through said second pathway to penetrate into thelower vertebral body; a locking member, said locking member selectivelymovable between an open position and a closed position in a movementpath that is generally transverse to said Y-axis, wherein upon saidtransverse movement to said closed position said locking member islocated anteriorly of said first straight anchor and said secondstraight anchor blocking their withdrawal from said anterior side ofbody portion; and, wherein said locking member is selectively movablealong said generally transverse movement path from said closed positionto said open position to allow withdrawal of said first straight anchorand said second straight anchor from said anterior side of body portionto facilitate removal of the body portion from between the upper andlower vertebral bodies.
 2. The intervertebral implant of claim 1,wherein said locking member comprises a lateral gate, and wherein saidmovement path is with said lateral gate pivoting on a hinge axis.
 3. Theintervertebral implant of claim 1, wherein said locking member comprisesa lateral slide, and wherein said movement path is along a track that isgenerally transverse to said Y-axis.
 4. The intervertebral implant ofclaim 1, wherein said locking member comprises a cam, and wherein saidmovement path is with said cam pivoting on a cam axis which is generallyparallel to said Y-axis, wherein said cam has a radially extendedsegment that, upon pivoting on said cam axis, is movable generallytransverse to said Y-axis to block said first straight anchor and saidsecond straight anchor from withdrawal.
 5. The intervertebral implant ofclaim 1, wherein said first straight anchor includes an opening, andwherein said opening is configured to receive a removal tool forremoving said first straight anchor from between the upper vertebralbody and the lower vertebral body.
 6. The intervertebral implant ofclaim 1 wherein, said first straight anchor has a first front edge thatextends anteriorly of a front surface along said anterior side of saidbody portion when implanted and penetrating into the upper vertebralbody; and, said second straight anchor has a second front edge thatextends anteriorly of said front surface along said anterior side ofsaid body portion when implanted and penetrating into the lowervertebral body.
 7. The intervertebral implant of claim 6 wherein, saidfirst straight anchor includes a first means for being grabbed by a toolfor anterior withdrawal from said body portion; and, said secondstraight anchor includes a second means for being grabbed by a tool foranterior withdrawal from said body portion.
 8. The intervertebralimplant of claim 7 wherein, said first means for being grabbed comprisesa first hole in said first straight anchor located near said first frontedge; and, said second means for being grabbed comprises a second holein said second straight anchor located near said second front edge. 9.The intervertebral implant of claim 1 wherein said body portion is madeof a metallic material having a Rockwell hardness [on the A-scale] of atleast 35 making it resistant to destructive implant removal.
 10. Theintervertebral implant of claim 1 wherein, said first straight anchordoes not have a detent lock for locking it permanently in place withinsaid first pathway; and, said second straight anchor does not have adetent lock for locking it permanently in place within said secondpathway.
 11. The intervertebral implant of claim 1, wherein said firstpathway and said second pathway are positioned on the same horizontalplane at said anterior side of said body portion.
 12. The intervertebralimplant of claim 1, further comprising: an insertion tool including afirst straight insertion pathway and a second straight insertionpathway, wherein said insertion pathways are adapted to receive one ofsaid first straight anchor or a second straight anchor; a tamp, whereinan end of said tamp is angled so that the end of said tamp may beinserted into said insertion pathways.
 13. The intervertebral implant ofclaim 1, wherein said body portion includes a plate that is removablyattachable to said body portion, and wherein said first pathway and saidsecond pathway extend through said plate.
 14. An intervertebral implantfor implantation between an upper vertebral body and a lower vertebralbody, comprising: a body portion having a top side for contact with theupper vertebral body and a bottom side for contact with the lowervertebral body and an anterior side between said top and bottom sides; aplate removably attachable to said body portion, said plate including atop side for contact with the upper vertebral body and a bottom side forcontact with the lower vertebral body and a posterior side and ananterior side between said top and bottom sides, wherein said platedefines in space a Z-axis generally in a cranial-caudal orientationtherethrough and a Y-axis perpendicular to said Z-axis and passingthrough said anterior side of said plate; a first pathway through saidplate, said first pathway extending from said anterior side of saidplate to said top side of said plate; a first straight anchor movable inan straight path through said first pathway to penetrate into the uppervertebral body; a second pathway through said plate, said second pathwayextending from said anterior side of said plate to said bottom side ofsaid plate; a second straight anchor movable in an straight path throughsaid second pathway to penetrate into the lower vertebral body; whereinsaid first straight anchor includes a first front edge that extendsanteriorly of a front surface along said anterior side of said platewhen said first straight anchor is implanted and penetrating into theupper vertebral body, and wherein said first straight anchor comprises afirst hole located near said first front edge for being grabbed by atool for anterior withdrawal from said plate; and, wherein said secondstraight anchor includes a second front edge that extends anteriorly ofa front surface along said anterior side of said plate when said secondstraight anchor is implanted and penetrating into the upper vertebralbody, and wherein said second straight anchor comprises a second holelocated near said second front edge for being grabbed by a tool foranterior withdrawal from said plate.
 15. The intervertebral implant ofclaim 14, wherein said anterior side of said body portion includes athreaded connection interface that may be mated with a threadedconnection interface on said posterior side of said plate to attach saidbody portion to said plate.
 16. The intervertebral implant of claim 14wherein said body portion and said plate are made of a metallic materialhaving a Rockwell hardness [on the A-scale] of at least 35, making itresistant to destructive implant removal.
 17. The intervertebral implantof claim 14 wherein, said first straight anchor does not have a detentlock for locking it permanently in place within said first pathway; and,said second straight anchor does not have a detent lock for locking itpermanently in place within said second pathway.
 18. The intervertebralimplant of claim 14 further comprising: a locking member selectivelymovable between an open position and a closed position in a movementpath that is generally transverse to said Y-axis, wherein upon saidtransverse movement to said closed position said locking member islocated anteriorly of said first straight anchor and said secondstraight anchor blocking their withdrawal from said anterior side ofsaid plate; and, wherein said locking member is selectively movablealong said generally transverse movement path from said closed positionto said open position to allow withdrawal of said first straight anchorand said second straight anchor from said anterior side of said plate tofacilitate removal of the intervertebral implant from between the upperand lower vertebral bodies.
 19. The intervertebral implant of claim 18,wherein said locking member comprises a lateral gate, and wherein saidmovement path is with said lateral gate pivoting on a hinge axis. 20.The intervertebral implant of claim 18, wherein said locking membercomprises a cam, and wherein said movement path is with said campivoting on a cam axis which is generally parallel to said Y-axis,wherein said cam has a radially extended segment that, upon pivoting onsaid cam axis, is movable generally transverse to said Y-axis to blocksaid first straight anchor and said second straight anchor fromwithdrawal.
 21. The intervertebral implant of claim 18, wherein saidlocking member comprises a lateral slide, and wherein said movement pathis along a track that is generally transverse to said Y-axis.